The celebration of World Environment Day will encourage governments, industries, communities and individuals to unite to find solutions that can reduce contaminating gases. One of the solutions is rehabilitation of buildings so that cities can be energetically sustainable by 2030.

Currently, buildings consume 30% of the energy and produce 28% of the CO2 emissions, according to data from the report by the company, Rockwool.
These numbers indicate that buildings are not very efficient. Practically all buildings need to improve in terms of features and insulation. The report by the International Energy Agency (IEA) calculates that 97% of buildings require some kind of intervention in order to be sustainable. This means that to reach objectives set by the European Union, investment must double before 2050.
Buildings have a more profitable potential to reduce carbon emissions than other sectors. It is for this reason that the rehabilitation of existing buildings with new insulation materials is given as one of the most economic solutions to save energy and, consequently, reduce greenhouse gases and air pollution.
According to the forecasts of the IEA, the energetic demand will increase up to 27% before 2040, an amount that could duplicate if consumption does not increase its efficiency.
Another study done by the company Monitor Deloitte in collaboration with Endesa and centered on Spain, concludes that 40% of the final energy of the country is consumed by cities, causing greenhouse gas emissions reaching 30% of the total.
Spanish cities count for 70% of the population and consume 40% of the final energy and therefore should be the launching point for energetic transition in our country. Taking steps and transforming habits of residents such as promoting the use of public transportation and rehabilitating intelligent buildings, both public and private, are the main modifications necessary to reach sustainability. Developing all these actions requires an additional investment of between 1,500 and 4,000€ per inhabitant from now until 2030.
Both studies conclude that, at the current rate of society, the objectives of sustainability agreed upon in Paris will not be reached coherent on keeping the increase of the average world temperature far below the 2 °C with regard to preindustrialist levels.